JP3352982B2 - Rendering method and device, game device, and computer-readable recording medium for storing program for rendering three-dimensional model - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to computer graphics (CG), and more particularly, to a method and an apparatus for rendering a three-dimensional model arranged in a virtual three-dimensional space and its outline, and a rendering program. Computer-readable recording medium.

[0002]

2. Description of the Related Art In recent years, non-photorealistic rendering techniques have been studied in the field of computer graphics. This non-realistic rendering technique is intended to represent a handwritten image by CG. One of them is an image generation technology that automatically draws the contour line of the three-dimensional model automatically even when the viewpoint position, line-of-sight direction, or arrangement position, direction, shape, etc. of the three-dimensional model in the virtual three-dimensional space is changed. Have also been studied in various ways.

For example, Japanese Patent Laid-Open No. 7-85310 discloses that
A technique is described in which, when a three-dimensional model is rendered, a contour is drawn by detecting whether or not each side is a contour part in units of sides of a polygon constituting the three-dimensional model. Also, Japanese Patent Application Laid-Open No. Hei 7-160905 discloses a technique in which each pixel in a display image on which the three-dimensional model is rendered is detected as a unit to detect whether each pixel is a contour part and draw a contour line. .

[0004]

As described above, according to the prior art, in order to draw an outline, a process of decomposing a three-dimensional model into units of polygon sides or pixels to be rendered and detecting an outline portion is performed. is necessary. Therefore, the process of drawing the contour line is very complicated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rendering method and apparatus and a rendering method and apparatus for rendering contour lines of a three-dimensional model arranged in a virtual space by simple processing.
An object of the present invention is to provide a computer-readable recording medium for storing a program.

[0006]

According to a first aspect of the present invention, there is provided a method for rendering a three-dimensional model composed of a plurality of surfaces which are arranged in a virtual space and have the outside of an object to be represented as a table. A first step of acquiring a second three-dimensional model corresponding to the first three-dimensional model, a second step of inverting each surface of the second three-dimensional model to generate a contour drawing model, and a first three-dimensional model And a third step of arranging the contour drawing model at a position including the first three-dimensional model from a given viewpoint position, and a surface of the contour drawing model facing the table position with respect to the viewpoint position. And a fourth step of drawing only a predetermined color scheme.

A rendering method according to a second aspect of the present invention includes a first step of acquiring a contour drawing model corresponding to a three-dimensional model and having a surface corresponding to each side of the three-dimensional model reversed, A second step of arranging the contour drawing model at a position including the model, and drawing the three-dimensional model from a given viewpoint position; Drawing in a predetermined color scheme.

In the present invention, only the surface facing the front side with respect to the viewpoint position of the contour drawing model whose front and back are reversed is drawn. Therefore, a portion of the contour drawing model that does not overlap with the three-dimensional model when viewed from the viewpoint position is drawn as a contour line.

The above-mentioned first step is a step of obtaining a contour drawing model corresponding to the three-dimensional model, having a size larger than that of the three-dimensional model, and having the surfaces corresponding to the respective surfaces of the three-dimensional model reversed. It is also possible. Similarly, the first step is performed by reversing the vertices corresponding to the three-dimensional model and corresponding to the respective surfaces of the three-dimensional model in the normal direction of the vertices of the vertices of the surfaces constituting the three-dimensional model. May be a step of acquiring a contour drawing model in which is set.

The color of the contour drawing model may be defined at the first step, the color of the three-dimensional model may be taken over, or the color may be defined at the time of actual drawing.

In the first step, the texture corresponding to the three-dimensional model, which has a pattern including a change in brightness or transparency, is mapped, and the surface corresponding to each surface of the three-dimensional model is inverted. It may be a step of acquiring a drawing model. When such texture mapping is performed, the contour line to be drawn has a handwritten tone.

In a rendering method according to a third aspect of the present invention, a first step of acquiring a contour drawing model corresponding to a three-dimensional model and a second step of arranging the contour drawing model at a position including the three-dimensional model And drawing a three-dimensional model from a given viewpoint position, and drawing only a surface of the contour drawing model facing the viewpoint position in a predetermined color scheme.

The difference from the second mode is the front and back of the surface of the contour drawing model. In order to draw a three-dimensional model as usual, it is necessary to prevent the three-dimensional model from being hidden from the viewpoint position by the contour drawing model. For this reason, in the second embodiment, the front and back of the surface of the contour drawing model are reversed from the corresponding surface of the three-dimensional model, and the back surface is excluded from the drawing target. In the third aspect, since the front and back of the surface of the contour drawing model are the same as the three-dimensional model, the same effect is obtained by drawing only the back surface as a drawing target when drawing.

The second step described above may be a step of enlarging the size of the contour drawing model obtained in the first step and arranging the contour drawing model at a position including the three-dimensional model. It is.

In a third aspect of the present invention, the contour drawing is performed by moving each vertex of the surface constituting the contour drawing model obtained in the first step described above in the normal direction of the vertex. The method further includes a fourth step of enlarging the size of the contour model, and the second step described above may be a step of arranging the contour drawing model enlarged in the fourth step at a position including the three-dimensional model. It is. A method of obtaining the normal of the surface and moving the surface in the normal direction is also conceivable, but additional processing for filling the space between the surfaces is required.

Further, the second step described above can be a step of reducing the size of the three-dimensional model and arranging the contour drawing model at a position including the three-dimensional model. Since it is sufficient that the contour drawing model is relatively larger than the three-dimensional model, the three-dimensional model may be reduced.

In the third step described above, the three-dimensional model is drawn from a given viewpoint position, and the brightness or the brightness of only the surface of the contour drawing model that faces the viewpoint position is determined. A step of mapping a texture having a pattern including a change in transparency and drawing the surface may be considered. When such texture mapping is performed, the contour line to be drawn has a handwritten tone.

According to a fourth aspect of the present invention, there is provided a program for rendering a three-dimensional model composed of a plurality of planes which are arranged in a virtual space and have the outside of an object to be represented as a table. A first step of acquiring a contour drawing model in which the front and back of a surface corresponding to each surface of the three-dimensional model are reversed, a second step of arranging the contour drawing model at a position including the three-dimensional model, A third step of drawing a model from a given viewpoint position and drawing only a surface of the contour drawing model that faces the table with respect to the viewpoint position in a predetermined color scheme. is there.

In the fourth aspect of the present invention, the modification of the first step described in the second aspect is applicable.

The rendering according to the fifth aspect of the present invention
The program causes the computer to acquire a contour drawing model corresponding to the stereo model, a second step of arranging the contour drawing model at a position including the stereo model, and , And a third step of drawing only the surface of the contour drawing model facing the viewpoint position with a predetermined color scheme.

The above-mentioned first step can be a step of acquiring a contour drawing model corresponding to the three-dimensional model and having a larger size than the three-dimensional model.

The modifications such as the second step and the third step described in the third embodiment can be applied to the fifth embodiment of the present invention.

The programs according to the fourth and fifth aspects of the present invention are stored in a recording medium such as a CD-ROM, a floppy disk, a memory cartridge, a memory, a hard disk, or a storage device. By causing a computer to read the program stored in the recording medium or the storage device in this manner, a rendering device and a game device described below can be realized. In addition, the recording medium enables the software to be easily distributed and sold as a software product independently of the device. Further, by executing this program using hardware such as a computer, the graphics technology of the present invention can be easily implemented with these hardware.

According to a sixth aspect of the present invention, there is provided a rendering apparatus which renders a three-dimensional model composed of a plurality of surfaces which are arranged in a virtual space and have the outside of an object to be represented as a table. Acquisition means for acquiring a contour drawing model in which the surfaces corresponding to the respective surfaces of the three-dimensional model are reversed, placement means for arranging the contour drawing model at a position including the three-dimensional model, and And drawing means for drawing only the surface of the contour drawing model facing the table with respect to the viewpoint position with a predetermined color scheme. The modification according to the second aspect of the present invention can be applied to the rendering device.

By causing a computer to execute each step in the rendering method according to the second aspect of the present invention, it is possible to obtain the same effect as the above-described rendering method. Therefore, by executing the described processing steps using hardware such as a computer, the rendering technology of the present invention can be easily implemented with these hardware.

The rendering apparatus according to a seventh aspect of the present invention comprises: an acquiring unit for acquiring a contour drawing model corresponding to the three-dimensional model; and an arranging unit for arranging the contour drawing model at a position including the three-dimensional model. Drawing means for drawing a three-dimensional model from a given viewpoint position, and drawing only a surface of the contour drawing model facing the viewpoint position in a predetermined color scheme.

The modification according to the third aspect of the present invention can be applied to the rendering apparatus. Third of the present invention
By causing a computer to execute each step in the rendering method according to the aspect, it is possible to obtain the same effect as the above-described rendering method. Therefore, by executing the described processing steps using hardware such as a computer, the rendering technology of the present invention can be easily implemented with these hardware.

According to an eighth aspect of the present invention, there is provided a game apparatus for rendering a three-dimensional model composed of a plurality of planes each of which is arranged in a virtual space and has the outside of an object to be represented as a table. A computer-readable recording medium storing a program to be executed. Then, the program has an acquisition function for acquiring a contour drawing model in which a front side and a back side of a surface corresponding to each surface of the three-dimensional model correspond to the three-dimensional model, and a contour drawing at a position including the three-dimensional model. Function for arranging the model for drawing and drawing for drawing the three-dimensional model from a given viewpoint position and drawing only the surface of the contour drawing model facing the table with respect to the viewpoint position with a predetermined color scheme Function. In this game device,
The modifications described in the second aspect of the present invention can be applied.

A game device according to a ninth aspect of the present invention includes a computer and a computer-readable recording medium storing a program to be executed by the computer. Then, the program provides the computer with an acquisition function of acquiring a contour drawing model corresponding to the three-dimensional model, an arrangement function of placing the contour drawing model at a position including the three-dimensional model, and A drawing function of drawing from a position and drawing only a surface of the contour drawing model facing the viewpoint position with a predetermined color scheme is executed. The modification according to the third aspect of the present invention can be applied to the game device.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the present invention is applied to a computer.
FIG. 1 shows an example of a computer 1000 that executes the computer program when the program is implemented by a program. The computer 1000 includes a computer main body 101.
Is the arithmetic processing unit 10 connected to the internal bus 119
3, memory 105, hard disk drive HDD1
07, sound processing unit 109, graphics processing unit 1
11, a CD-R drive 113, a communication interface 115, and an interface unit 117.

The sound processing unit 109 of the computer main body 101 has a sound output device 125 as a speaker.
In addition, the graphics processing unit 111 is connected to a display device 121 having a display screen 122. CD-R
A CD-R 131 can be mounted on the drive 113. The communication interface 115 connects to the network 151 via the communication medium 141. Interface section 117
Is connected to the input device 161.

The arithmetic processing unit 103 includes a CPU, a ROM, and the like, executes programs stored on the HDD 107 and the CD-R 131, and controls the computer 1000. The memory 105 is a work area of the arithmetic processing unit 103. The HDD 107 is a storage area for storing programs and data. When the program executed by the arithmetic processing unit 103 instructs to output a sound, the sound processing unit 109 interprets the instruction and outputs a sound signal to the sound output device 125.

[0033] The graphics processing unit 111 controls the display device 1 in accordance with the drawing command output from the arithmetic processing unit 103.
A signal for display on the display screen 122 is output. The CD-R drive 113 reads and writes programs and data from and to the CD-R 131. The communication interface 115 connects to the network 151 via the communication medium 141 and communicates with another computer or the like.
The interface unit 117 outputs an input from the input device 161 to the memory 105, and the arithmetic processing unit 103 interprets the input and performs arithmetic processing.

The program and data according to the present invention are initially stored in, for example, the CD-R 131. The program and data are stored in the CD-R drive 11 at the time of execution.
3 and loaded into the memory 105.
The arithmetic processing unit 103 processes the program and data according to the present invention loaded into the memory 105, and outputs a drawing command to the graphics processing unit 111. The intermediate data is stored in the memory 105. The graphics processing unit 111 performs processing in accordance with the drawing command from the arithmetic processing unit 103 and outputs a signal for displaying on the display screen 122 of the display device 121.

Next, an example of the graphics processing section 111 shown in FIG. 1 will be described in detail with reference to FIG. The graphics processing unit 111 includes a bus control unit 201 that exchanges data with the internal bus 119, a geometric operation unit 207 that exchanges data with the bus control unit 201, and a triangle rendering processing unit 2.
05, a pixel color processing unit 209 that receives data from the triangle drawing processing unit 205 and performs processing, a Z buffer 211 that stores the Z value of each pixel and is used by the pixel color processing unit 209, and a pixel color processing unit 209 And a frame buffer 213 for storing the display screen data from the CPU. Note that the frame buffer 21
3 is output to the display device 121.

The bus control unit 201 of the graphics processing unit 111 receives the drawing command output from the calculation processing unit 103 via the internal bus 119, and receives the geometric calculation unit 207 or the triangle drawing processing in the graphics processing unit 111. Part 20
5 is output. In some cases, a process for outputting the output of the geometric operation unit 207 or the triangle drawing processing unit 205 to the memory 105 via the internal bus 119 is also performed. The geometric operation unit 207 performs geometric operations such as coordinate conversion, light source calculation, rotation, and reduction / enlargement. The geometric operation unit 207 outputs the result of the geometric operation to the triangle drawing processing unit 205.

The triangle drawing processing unit 205 generates data at each point inside the triangle polygon by interpolating the data of each vertex of the triangle polygon. The pixel color processing unit 209 writes a display image to the frame buffer 213 using the data at each point inside the triangle polygon generated by the triangle drawing processing unit 205. At this time, the pixel color processing unit 209 performs hidden surface elimination using the Z buffer 211.

For example, the arithmetic processing unit 103 outputs, to the graphics processing unit 111, a drawing command for performing perspective transformation and light source calculation, using data on the position, color, and light source of each vertex of a triangular polygon in the world coordinate system as data. In such a case, the following processing is performed in the graphics processing unit 111. Upon receiving the drawing command, the bus control unit 201 outputs the command to the geometric operation unit 207. The geometric operation unit 207 performs a perspective transformation and a light source calculation, and calculates the coordinate values (Z
Value) and color. The geometric operation unit 207 outputs the calculation result to the triangle drawing processing unit 205.

The triangle drawing processing unit 205 calculates the coordinate value (including the Z value) and the color of each pixel inside the triangular polygon using the coordinate value (including the Z value) and the color at each vertex of the triangle polygon. . Further, the triangle drawing processing unit 205 outputs the coordinate value (including the Z value) and the color of each pixel to the pixel color processing unit 209. The pixel color processing unit 209 reads the current Z value of the pixel from the Z buffer 211, and
Is compared with the Z value output from. If the output Z value is smaller than the current Z value, the pixel color processing unit 2
In step 09, the output Z value is stored in the storage position in the Z buffer 211 corresponding to the pixel, and the color of the pixel is stored in the storage position in the frame buffer 213 corresponding to the coordinate value of the pixel.

In some cases, transparency is set for the color of the pixel. In this case, the pixel color processing unit 209 combines the color stored in the storage position in the frame buffer 213 corresponding to the coordinate value of the pixel and the color of the pixel based on the transparency. As a result, a composite color is generated. The pixel color processing unit 209 stores the generated composite color in the same storage location as before.

Each embodiment described below is implemented by the computer shown in FIG.

1. First Embodiment Next, an outline of a first embodiment of the present invention will be described with reference to a functional block diagram of FIG. The rendering apparatus illustrated as the first embodiment includes a contour drawing model acquisition unit 300, a contour drawing model arrangement matrix setting unit 305, a contour drawing model processing unit 310, a blurred expression texture mapping unit 320, a hidden surface erasing process. A pixel processing unit 330 including a unit 335 and a three-dimensional model processing unit 340 are included.

The contour drawing model acquisition section 300 generates a contour drawing model corresponding to a three-dimensional model constituted by, for example, triangular polygons. If the contour drawing model has been generated in advance, the contour drawing model acquisition unit 30
0 reads out the previously generated contour drawing model composed of triangular polygons. In addition, each surface of the acquired contour drawing model is upside down from the corresponding surface of the three-dimensional model. The contour drawing model is larger than the three-dimensional model, and is defined by a predetermined color scheme for the contour line. Note that the contour drawing model must ultimately be relatively larger than the corresponding stereo model, but the size of the contour drawing model at this stage may be the same as the stereo model. In this case, by the time the contour drawing model and the three-dimensional model are drawn, processing is performed so that the contour drawing model is drawn relatively larger than the three-dimensional model.
Further, the color of the contour drawing model may take over the color of the material of the corresponding three-dimensional model as it is. In this case, the drawing color is specified separately.

The reference position of the contour drawing model is usually defined to be the same as or near the reference position of the corresponding solid model. For example, FIG. 4 shows a case where the size of the contour drawing model 510 is defined to be slightly larger than the size of the three-dimensional model 500. In FIG. 4, the arrow direction of each surface indicates the front surface. The three-dimensional model 500 has a front surface outside each hexagonal surface, and the contour drawing model 510 has a front surface inside each hexagonal surface.

The three-dimensional model reference position 520, which is the reference position of the three-dimensional model 500, and the contour drawing model reference position 530, which is the reference position of the contour drawing model 510, are both defined at the center of each model. The contour drawing model 510
Is defined to be slightly larger than the three-dimensional model 500 around the contour drawing model reference position 530.

Then, the contour drawing model arrangement matrix setting section 305 (FIG. 3) sets the contour drawing model reference position 530 in the virtual space to the three-dimensional drawing model reference position 5.
An arrangement matrix to be arranged at the same position as 20 is set. That is, by setting the arrangement matrix of the contour drawing model 510 so as to include a transformation for translating the contour drawing model reference position 530 to the coordinates of the three-dimensional model reference position 520, the position of the three-dimensional model 500 is set to a position that includes the three-dimensional model 500. A contour drawing model 510 is arranged.

The contour drawing model processing section 310 carries out vertex conversion (enlargement / reduction / rotation / translation / perspective transformation) for each vertex of the contour drawing model, and performs each surface (or (Front / back) of the polygon. For the vertex conversion, the above-described arrangement matrix is also used. Note that the light source calculation is not performed here. For example,
In addition to performing enlargement / reduction / rotation / translation / perspective transformation in accordance with a designated state in a virtual space which is a virtual three-dimensional space, the contour drawing model acquisition unit 300 is used for drawing a contour having the same size as the three-dimensional model. When the model is obtained, the contour drawing model processing unit 310 performs vertex conversion for enlarging the size of the contour drawing model. FIG. 4 also shows the relationship between the three-dimensional model and the contour drawing model in the case of enlargement.

The front / back determination of the surface is performed to exclude a surface whose front direction is the same as the direction of the line of sight 540 from the camera 550 from the drawing target. In the example of FIG. 4, the surface 5 near the camera 550 of the contour drawing model 510
11 and 512 are out of the drawing target. By doing so, the surface outside the three-dimensional model 500 and close to the camera 550 is excluded from the drawing target, and the three-dimensional model 500 is drawn as usual. On the other hand, the contour drawing model 510
Are the faces 513, 514, 5 behind the three-dimensional model 500.
Only 15 and 516 are to be drawn. However, since the hidden surface is removed by the hidden surface removal processing unit 335 of the pixel processing unit 330, not all of the surface is drawn even if it becomes a drawing target.

Blurred expression texture mapping section 320
Performs a process for mapping a blurred expression texture to a contour drawing model so that the resulting contour line becomes a blurred line. This blur expression texture is a texture having a design including a change in brightness or transparency, and an example will be described later. Since the outline does not always need to be blurred, the blurred expression texture mapping unit 320 is selectively operated.

The three-dimensional model processing unit 340 performs a three-dimensional model process. That is, the three-dimensional model processing unit 3
40 is a vertex transformation (enlargement /
Reduction / rotation / translation / perspective transformation) and light source calculation are performed, and the front and back of each surface (or polygon) of the three-dimensional model is determined. In addition to performing enlargement / reduction / rotation / translation / perspective transformation in accordance with the state specified in the virtual three-dimensional space, the contour drawing model processed by the contour drawing model processing unit 310 is the same as the stereo model. If the size is the size, the three-dimensional model processing unit 340 performs vertex conversion for reducing the size of the three-dimensional model so that the three-dimensional model is relatively smaller than the contour drawing model.

FIG. 4 shows the relationship between the three-dimensional model 500 and the contour drawing model 510 even when the three-dimensional model processing unit 340 performs the reduction process. The determination of the front and back of the surface is the same as that of the contour drawing model processing unit 310, and the surface of the three-dimensional model whose front direction is the same as the camera's line of sight is excluded from the drawing target. In the example of FIG. 4, the rear surfaces 503, 504, 505, and 506 viewed from the camera.
Are excluded from the drawing target.

The pixel processing section 330 performs a drawing process for each pixel. For example, the pixel processing unit 330 obtains the color of each pixel in the plane by interpolating from the color of the vertex of the plane,
The color of each pixel is determined while performing the hidden surface removal processing using the buffer. The pixel processing unit 330 performs the process on the surface to be drawn by the contour drawing model processing unit 310 and the three-dimensional model processing unit 340.

For example, in the case of FIG.
The two surfaces 501 and 502 closest to the camera 550 of the contour drawing model are drawn,
Two surfaces 513, 514, 515 and 516 are drawn. When viewed from the camera 550, these four surfaces of the contour drawing model 510 protrude left and right from the three-dimensional model 500, so that only the protruding portions are drawn without erasing the hidden surface. This protruding part becomes the contour line. Note that the pixel processing unit 330 determines the color in consideration of the color of the material of the contour drawing model. In some cases, the color of the outline (black or dark outline color) is used as the color of the outline drawing model, ignoring the color of this material altogether.

Next, a processing flow for the first embodiment will be described. The following processing is performed by the arithmetic processing unit 103
FIG. 1 shows a process executed by controlling other elements in the computer main body 101.

[CD-R Recording Process] FIG. 5 shows a process of generating a contour drawing model performed in advance. When the process starts, data of the three-dimensional model stored in the HDD 107 in advance is read (step S303), and is acquired as a conversion target model.

Next, the size of the model to be converted is enlarged so as to be slightly larger (step S30).
5). For example, in the normal direction of each vertex of the conversion target model,
The vertex is moved by a length of 2% of the total length of the conversion target model, and is enlarged by about 2% as a whole. That is, for example, if the conversion target model is a humanoid and the height is equivalent to 1.8 m, each vertex is 0.0
It is moved by a length corresponding to 36 m. When the enlargement ratio is larger, the outline is drawn thicker, and when the enlargement ratio is smaller, and when the conversion target model is only slightly enlarged, the outline is drawn thinner. Furthermore, if the part is not uniform and is partially enlarged, only the outline of the enlarged part is drawn thick. Since this size adjustment is usually performed by the maker of the three-dimensional model, a contour line reflecting the intention of the maker can be drawn.

If the normal of each vertex of the three-dimensional model is not defined, the normal of the vertex obtained by interpolating the normal of each face sharing the vertex is used to calculate the vertex of the vertex. Can be moved in the normal direction of the vertex. In addition, the plane can be moved in the normal direction of each plane of the three-dimensional model. However, if the surface is simply moved, a gap is generated between the surfaces, and a process for filling the gap is required separately. Furthermore, since a reference position is usually defined in the three-dimensional model, each vertex of the conversion target model can be moved around the reference position of the corresponding conversion target model.

Next, the color of the material on each surface of the model to be converted is set to a color having the same saturation but lower brightness (step S307). Note that all the surfaces may be set to a single color such as black. Further, the setting for mapping the texture for faint expression may be performed. Since the color of the material is adjusted by the maker,
The outline can be drawn in the color intended by the maker.

Next, the front and back of each side of the model to be converted are reversed (step S309). More specifically, the order in which the vertices of each triangle constituting the conversion target model are defined is changed by one place. The details of the front / back determination method will be described later.

The data of the model to be converted thus far is used as the contour drawing model data in the HDD 107.
(Step S311), and the contour drawing model generation process ends (step S313).

Next, various data including the contour drawing model data stored in the HDD 107 is written to the CD-R 131 by the CD-R drive 113. FIG.
2 schematically shows an example of data written on the CD-R 131.

The program area 132 stores a program for causing the computer 1000 to carry out the present invention. However, the program for implementing the present invention is a CD-ROM.
Processing until writing to R131 and FIG.
Can be divided into the processing shown in FIG. Therefore, the contour drawing model described above is generated and the contour drawing model
A program for writing various data including data into the CD-R 131 may not be included here.
By doing so, the processing shown in FIG.
The present invention can also be implemented on a computer other than the computer 1000 having a CD-ROM drive instead of the DR drive 113.

The system data area 133 stores various data processed by the program stored in the program area 132 described above. The image data area 134 stores data including the contour drawing model data 135. However, when the contour drawing model is generated in the contour drawing model acquisition processing described later,
There is no need to store the contour drawing model data 135. It should be noted that data such as a three-dimensional model and a texture expressing blur are also stored in the image data area 134.

In the sound data area 136, the sound processing unit 109 shown in FIG.
25 stores data for outputting a sound. Since the sound processing is not directly related to the present invention, it is not necessary to store data in the sound data area 136.

Note that the size of the contour drawing model stored in the CD-R 131 may be defined to be the same as the size of the corresponding stereo model. In this case,
After the contour drawing model is acquired in the contour drawing model acquisition processing described later, the contour drawing model is enlarged until the arrangement matrix of the contour drawing model is set in the contour drawing model placement processing described later. Is done. Or,
When the arrangement matrix of the contour drawing model is set in the contour drawing model arrangement processing, the arrangement matrix may be determined so that the arrangement matrix includes the enlargement conversion. Conversely, when arranging the three-dimensional model, the three-dimensional model arrangement matrix may be determined so that the three-dimensional model arrangement matrix includes the reduction conversion.

The color of the material of each surface of the contour drawing model stored in the CD-R 131 may be the same as the color of the material of each surface of the corresponding three-dimensional model. In this case, the contour drawing model is drawn in a separately defined color such as, for example, black when drawing the contour drawing model described later.

[Overall Processing Flow] FIG. 7 shows the first embodiment.
2 shows the entire processing flow. When the process starts, initialization is performed (step S2). The processing of the initial setting includes data acquisition processing of a contour drawing model (FIG. 8) described later in detail and data acquisition processing of a three-dimensional model to be drawn. Then, the state in the virtual space is set (step S3). This process is, for example, a process of changing the state in the virtual space when the position of the viewpoint is changed, the position of the light source is changed, the model is moved, or the model is deformed. By performing this processing, the position coordinates of the three-dimensional model and the contour drawing model
A process for determining the direction, enlargement ratio, reduction ratio, and the like is performed. More specifically, a process of determining an arrangement matrix (used in FIG. 10) of the three-dimensional model and the contour drawing model is performed. Further, in step S3, whether or not contour drawing is to be performed in step S4 is performed in accordance with a key operation of the input device 161 (FIG. 1).

Next, a process for determining whether or not to draw an outline is performed (step S4). This is determined based on the setting by the key operation of the input device 161 or the setting by another program as described above. When it is determined that the contour line is to be drawn, a drawing process of the contour line drawing model is performed (step S5). This will be described later with reference to FIG. Then, the drawing process of the three-dimensional model is performed whether or not the contour line is drawn (step S6). This processing will also be described later with reference to FIG. Steps S3 to S6 are repeatedly performed until the processing is completed (step S7). Whether or not the processing has ended is determined based on whether or not an operation input indicating that the processing should be ended has been performed.

[Contour Drawing Model Acquisition Processing] FIG.
The process of acquiring a contour drawing model is shown. Here, first, it is determined whether or not a contour drawing model is generated (step S203). This is because there are a case where the contour drawing model is prepared in advance and a case where the contour drawing model is generated at this stage. Here, this determination is made, for example, when the contour drawing model corresponding to the three-dimensional model is CD-R1.
This is performed by determining whether or not the data is stored in the storage 31. If it is determined that the model is stored, it is determined that the contour drawing model is not generated. If it is determined that the model is not stored, it is determined that the contour drawing model is generated.

If it is determined that the contour drawing model is not generated, the data of the contour drawing model stored in the CD-R 131 is read (step S20).
7). As described above with reference to FIGS. 4 and 5, each surface of the contour drawing model is a surface inverted from the corresponding surface of the three-dimensional model. The size of the contour drawing model to be read is defined to be slightly larger than the corresponding three-dimensional model. Further, the color of the contour drawing model is defined as a color darker than the corresponding three-dimensional model.

If it is determined that a contour drawing model is to be generated, a process for generating a contour drawing model is performed (step S205). Similarly to step S207, even when the contour drawing model is generated at this stage, the respective surfaces of the contour drawing model are, as described above with reference to FIG. Is turned upside down.

The size of the contour drawing model is slightly larger than the corresponding three-dimensional model. Step S30
Similarly to FIG. 5 (FIG. 5), for example, the vertex is moved in the normal direction of each vertex of the three-dimensional model, and an enlarged contour drawing model is generated. When the contour drawing model is larger than the stereo model, the contour is drawn thicker, and when the contour drawing model is only slightly larger than the stereo model, the contour is drawn thinner.

As described in the description of step S305 (FIG. 5), even if the plane is moved in the normal direction of each plane of the three-dimensional model, an enlarged contour drawing model is generated. Good. Further, an outline drawing model that is enlarged by moving each vertex of the stereo model around a reference position defined in the normal stereo model may be generated.

At this point, the size of the contour drawing model may be generated in the same size as the size of the corresponding three-dimensional model. In this case, after the contour drawing model is acquired in the contour drawing model acquisition processing, the contour drawing model is set until the arrangement matrix of the contour drawing model is set in the contour drawing model arrangement processing described later. Is expanded. Alternatively, when the arrangement matrix of the outline drawing model is set in the outline drawing model arrangement processing, the arrangement matrix may be determined so that the arrangement matrix includes the enlargement conversion. Conversely, when arranging the three-dimensional model, the three-dimensional model arrangement matrix may be determined so that the three-dimensional model arrangement matrix includes the reduction conversion.

On the other hand, the material color of each surface of the contour drawing model is generated as a darker color of the material of each surface of the corresponding three-dimensional model. Step S30
7 (FIG. 5), the color of the contour drawing model to be generated may not be defined at this point. Alternatively, the color of the material of each surface of the contour drawing model may be the same as the color of the material of each surface of the corresponding three-dimensional model. In this case, when the contour drawing model is drawn, the color of the contour drawing model is not considered, and the contour drawing model is drawn with a separately defined color such as, for example, black, or a color of a texture expressing blur. Is done.

Next, it is determined whether or not a texture representing a blur is mapped to the contour drawing model (step S209). When the contour drawing model is generated in step S205, the determination is performed based on the data of the corresponding three-dimensional model. On the other hand, when the contour drawing model is read in step S207,
The determination is performed based on the read data of the contour drawing model. If it is determined that a texture expressing blur is mapped, step S211 is executed.
Is mapped on the contour drawing model. That is, texture coordinates (U, V) are set for each vertex of the polygon.

As described above, the texture expressing the blur has a design including a change in brightness or transparency. FIG. 9 shows an example of a texture including a change in brightness. This is a texture having a pattern in which white diagonal lines are finely entered on a black background. Since the brightness of the black portion is low and the brightness of the white portion is high, the texture shown in FIG. 9 includes a change in brightness.

In the present invention, the outline is drawn by cutting out a part of the outline drawing model as a line. That is, when the contour drawing model to which the texture of FIG. 9 is mapped is drawn as a contour line, a line corresponding to a line cut out as a contour line from the contour drawing model is cut out from the texture and drawn. At this time, if a line is cut out from the texture in a substantially vertical direction or a substantially horizontal direction, each line includes a change in brightness. By drawing such a line as a contour, a contour including a change in brightness is drawn. That is, the blur of the outline is expressed, and a more hand-drawn outline is drawn.

In the case of the texture shown in FIG. 9, even if a line is cut out in any direction, the line includes a change in brightness. However, the brightness may hardly change depending on the cutting direction. Since it is possible to adjust which part of the contour drawing model is drawn in which direction as the contour, the texture of the texture expressing the blur is adjusted mainly according to the cutout direction.

When a contour is drawn by a contour drawing model on which a texture having a pattern including a change in transparency is mapped, the contour includes a change in transparency. A color close to the color of the background is drawn in a portion with high transparency according to the ratio, and a color close to the color of the texture, such as black, is drawn in a low portion. As a result, a contour line including a change in shading is drawn, and the blur of the contour line is expressed.

When it is determined that the texture representing the blur is not mapped, and when the processing for mapping the texture is completed, the arithmetic processing unit 103 ends the contour drawing model acquisition processing (step S21).
3).

[Contour Drawing Model Arrangement Processing] In step S3 of FIG. 7, the arrangement matrix of the contour drawing model is set, and the contour drawing model arrangement processing is performed.
Usually, the reference position of the contour drawing model is provided at a position corresponding to the reference position of the three-dimensional model. Then, an arrangement matrix of the contour drawing model is set such that the reference position of the contour drawing model is arranged at or near the reference position of the three-dimensional model.

When the direction of the three-dimensional model changes, an arrangement matrix including a rotation transformation is set for the contour drawing model so as to correspond to the change. When the shape of the three-dimensional model changes, a deformation process is performed so that the contour drawing model corresponds to the change.

At this stage, if the contour drawing model has the same size as the corresponding three-dimensional model, the contour drawing model is enlarged. More specifically, an arrangement matrix of the contour drawing model is set such that each vertex of the contour drawing model is enlarged and converted according to a predetermined enlargement ratio around the reference position of the contour drawing model. Or conversely, the three-dimensional model may be reduced. That is, in this case, the matrix for arranging the three-dimensional model is set such that each vertex of the three-dimensional model is reduced and converted in accordance with the predetermined reduction ratio with the reference position of the three-dimensional model as the center.

In this way, the relatively large contour drawing model is finally arranged so as to include the three-dimensional model. The contour drawing model may not completely include the three-dimensional model depending on the relationship between the arrangement positions, directions, shapes, and the like of the two models. However, even in such a case, an outline is drawn for the included part.

At this stage, it is not always necessary to set an arrangement matrix.
It is only necessary that the elements required for vertex conversion such as the direction and the enlargement / reduction ratio have been determined. Also in this case, the actual vertex conversion is performed at the stage of the rendering process of each model.

[Contour Drawing Model Drawing Processing] In FIG. 10 showing the drawing processing flow of the contour drawing model, the processing described below is repeatedly performed until all vertices of the contour drawing model are processed (step S503). ). The first process that is repeatedly performed is a vertex transformation (enlargement / reduction / rotation / translation / perspective transformation) of one vertex (step S505). Here, the arrangement matrix obtained in step S3 is also used in vertex conversion.

For example, this processing is performed by the geometric operation unit 207 instructed by the operation processing unit 103. It should be noted here that the geometric calculation unit 20 is used for the contour drawing model.
7 is that the light source calculation is not performed. This is because the contour line is drawn regardless of the position of the light source, and it is useless to calculate the light source. For example, the color of the material of the contour drawing model may be ignored. Normally, this vertex transformation is performed based on the state specified in the virtual three-dimensional space, but if the size of the contour drawing model is the same as the three-dimensional model, the vertex conversion is performed according to the arrangement matrix set in the arrangement processing At this stage, the outline drawing model may be enlarged and converted.

Then, it is determined whether or not the polygon (surface) including the vertex is a front surface (step S50).
7). This determination is made in the case of a triangular polygon based on which direction the triangular polygon composed of the two vertices processed before this vertex faces. FIG. 11 shows an example of a triangular polygon forming a three-dimensional model for explaining the method of determining front and back. In this example, the vertex number of the upper vertex in the figure is 0, the vertex number of the lower left vertex is 1, and the vertex number of the lower right vertex is 2.
That is, the vertex numbers are assigned counterclockwise from the upper vertex.

In the first embodiment, a surface that appears to have the vertex numbers of the respective vertices of the triangular polygon counterclockwise is defined as a front surface (a so-called right-handed system). Therefore, the front surface of the triangular polygon in FIG. Assuming that there is a normal vector in the direction of the front surface, the front and back of the triangular polygon can be determined by the sign of the inner product of the normal vector and the line-of-sight vector. In other words, if the sign of the inner product is positive, it means that the front surface is facing the viewpoint position, and if the sign of the inner product is negative, it means that the back surface is facing the viewpoint position. Become.

Actually, as shown in FIG. 12, the vector a from the vertex 0 projected to the screen to the vertex 1
And the cross product a × b of the vector b from the vertex 0 to the vertex 2 projected on the screen is calculated, and it is determined whether or not the front surface is in the direction of the vector n which is the result of the cross product. The vector n is parallel to the z-axis, and the sign of the z component of the vector n is inspected to determine whether or not the vector is a front surface. That is,
If it is positive, it is hospitality, and if it is negative, it is back. On the left side of FIG. 12, the numbers of the vertices of the triangle are counterclockwise, and the vector n, which is the result of the outer product, is oriented in the positive direction of the z-axis. On the other hand, on the right side of FIG. 12, the numbers of the vertices of the triangle are clockwise, and the vector n resulting from the cross product is likely to be in the negative direction of the z-axis.

In the case of the contour drawing model in the first embodiment, the surface of the contour drawing model is upside down from the corresponding surface of the three-dimensional model. FIG. 13 shows a polygon corresponding to the polygon of FIG. 11 and having its front and back reversed. Each vertex of the triangular polygon shown in FIG. 13 is assigned vertex numbers 0, 1, and 2 in the order of upper, lower right, and lower left in the figure. That is, the corresponding triangular polygon is shown in FIG.
Vertex numbers are assigned in the reverse order. Therefore, FIG.
In 3, the front side of the paper is determined to be the back side. In the first embodiment, the front / back determination is performed at this stage, but the front / back determination may be performed before this stage.

If the polygon (surface) including the vertex is a back surface, the flow returns to step S503. If the polygon (face) containing the vertex is a front face,
It is determined whether or not to map a texture expressing blur (step S509).

This means texture mapping for polygons. If the texture expressing the blur is mapped, the texture coordinates of the texture for expressing the blur for the vertex are calculated (step S511). When performing texture mapping, the texture coordinates (U, V) are already specified for the vertices of the polygon, but if the polygon is arranged at an angle to the screen, the texture is distorted on the screen. May be displayed. In order to avoid this distortion, S = U × Q and T = V × Q are calculated using Q = 1 / w (w is the depth from the screen) as the texture perspective processing. If the texture expressing the blur is not mapped, the process proceeds to step S513.

Then, for example, the triangle drawing processing unit 205 and the pixel color processing unit 209 shown in FIG. 2 are driven (step S513). As described above, the triangle rendering processing unit 205 interpolates the data of each vertex of the triangle polygon to generate data at each pixel inside the triangle polygon. The data of each vertex is a material color, a screen coordinate value, and a texture coordinate value if step S511 is performed. The data at each pixel is
If the color of the material and step S511 are executed, it is a texel color.

However, at this point, it is also possible to ignore the color of the material and set the color of the outline at each vertex.
It is also possible to set the luminance in consideration of the color of the material. The pixel color processing unit 209 uses the data of each pixel inside the triangular polygon generated by the triangle drawing processing unit 205 to generate the frame buffer 21.
3 is displayed. At this time, the hidden surface is erased using the Z buffer 211.

An example in which the Z buffer 211 is used for hidden surface elimination is shown. However, for a simple model as shown in FIG. 4, a hidden surface elimination process such as the Z sort method without using the Z buffer is performed. May be implemented. However, when a more complicated model, for example, a person's hand is arranged before the body, it is difficult to draw an outline accurately unless hidden surface removal using a Z buffer is performed. is there.

[3D Model Drawing Process] FIG. 14 shows a flow of a 3D model drawing process common to the first embodiment and a second embodiment described later. Here, the following processing is repeatedly performed until all vertices of the three-dimensional model are processed (step S603). The first processing to be repeated is vertex transformation (enlargement / reduction / rotation / translation / perspective transformation) and light source calculation for one vertex (step S60).
5). This is executed by the geometric operation unit 207 according to an instruction from the operation processing unit 103, for example. The data of the three-dimensional model is stored in the CD-R 131, for example.

The enlargement / reduction / rotation / translation / perspective transformation is basically based on the state in the virtual space set in step S3 of FIG. However, if the contour drawing model is the same size as the three-dimensional model, the contour drawing model may be relatively large by reducing the size of the three-dimensional model. In this case, reduction conversion is performed in step S605.
In addition, if each vertex is moved along the normal line toward the center of the three-dimensional model, it can be easily reduced. Here, the perspective transformation is for transforming the coordinate value of each vertex of the polygon in the world coordinate system into the coordinate value in the screen coordinate system. The light source calculation is for calculating a shadow (luminance) generated by a virtual light ray emitted from the light source.

Next, it is determined whether or not the polygon (surface) including the vertex is a front surface (step S607). This determination is made in the case of a triangular polygon based on which direction the triangular polygon composed of two vertices processed before this vertex faces. For this determination, the method described in the drawing processing of the contour drawing model can be used. In the first embodiment, the front / back determination is performed at this stage, but the front / back determination may be performed before this stage.

If the polygon (surface) including the vertex is a back surface, the flow returns to step S603. If the polygon (surface) including the vertex is the front surface, a process of calculating the texture coordinates of the vertex is performed (step S609). When the texture mapping process is performed, the vertex of the polygon already has the texture coordinates (U,
V) is designated, but as texture perspective processing, here, using Q = 1 / w (w is the depth from the screen), S = U × Q and T = V × Q are calculated. Will be However, whether or not to perform texture mapping is optional.

Then, for example, the triangle drawing processing unit 205 and the pixel color processing unit 209 shown in FIG. 2 are driven (step S611). As described above, the triangle rendering processing unit 205 interpolates the data of each vertex of the triangle polygon to generate data at each pixel inside the triangle polygon. The data of each vertex is a material color, a screen coordinate value, and a texture coordinate value. Also,
The data at each pixel is the material color and texel color. The pixel color processing unit 209 includes:
The display image is written to the frame buffer 213 using the data of each pixel inside the triangular polygon generated by the triangular drawing processing unit 205. At this time, the hidden surface is erased using the Z buffer 211.

When the above-described processing is performed, the three-dimensional model is rendered as usual, and the contour drawing model introduced in the first embodiment draws a portion behind the three-dimensional model that is not hidden by the three-dimensional model. So that part is rendered as a contour line. In the first embodiment, the outline can be easily drawn by performing substantially the same processing as that of a normal three-dimensional model only by introducing the outline drawing model.

2. Embodiment 2 An outline of Embodiment 2 of the present invention will be described with reference to a functional block diagram of FIG. The rendering device illustrated as the second embodiment includes a contour drawing model acquisition unit 400, a contour drawing model arrangement matrix setting unit 405, a contour drawing model processing unit 410 including a reversal front / back determination unit 415,
A blur expression texture mapping unit 420, a pixel processing unit 430 including a hidden surface elimination processing unit 435, and a stereo model processing unit 440 are included.

The contour drawing model acquisition section 400 generates a contour drawing model corresponding to, for example, a three-dimensional model constituted by triangular polygons. If the contour drawing model has been generated in advance, the contour drawing model acquisition unit 40
0 reads out the previously generated contour drawing model composed of triangular polygons. The second embodiment differs from the first embodiment in that each surface of the acquired contour drawing model has the same front and back surfaces as the corresponding surface of the three-dimensional model.
The contour drawing model is larger than the three-dimensional model, and is defined by a predetermined color scheme for the contour line. Note that the contour drawing model must ultimately be relatively larger than the corresponding stereo model, but the size of the contour drawing object at this stage may be the same as the stereo model. In this case, processing is performed such that the contour drawing model is drawn relatively larger than the stereo model by the time the contour drawing model and the stereo model are drawn.

In some cases, the color of the contour drawing model may take over the color of the material of the corresponding three-dimensional model as it is. In this case, the drawing color is specified separately. The reference position of the contour drawing model is usually defined to be the same as or near the reference position of the corresponding stereo model. For example, FIG. 16 shows a case where the contour drawing model 610 is defined to be slightly larger than the three-dimensional model 600. In FIG. 16, the arrow direction of each surface indicates the front surface. Both the three-dimensional model 600 and the contour drawing model 610 have a front surface outside each hexagonal surface.

The three-dimensional model reference position 620 as the reference position of the three-dimensional model 600 and the contour drawing model reference position 630 as the reference position of the contour drawing model 610 are both defined at the center of each model. Also, the contour drawing model 610 is used.
Is defined to be slightly larger than the three-dimensional model 600 around the contour drawing model reference position 630.

The contour drawing model placement matrix setting section 405 (FIG. 15) sets a placement matrix for placing the contour drawing model reference position 630 in the virtual space at the same position as the three-dimensional model reference position 620. Set. This arrangement matrix is used for conversion such as translation, rotation, enlargement / reduction, etc., with respect to each vertex of the corresponding model. In other words, by setting the arrangement matrix of the contour drawing model 610 to include a transformation for translating the contour drawing model reference position 530 to the coordinates of the stereo model reference position 520, the contour drawing is performed at a position that includes the stereo model 600. Model 610 is arranged.

The contour drawing model processing section 410 carries out vertex conversion (enlargement / reduction / rotation / translation / perspective conversion) for each vertex of the contour drawing model, and performs each surface (or (Front / back) of the polygon. For this vertex conversion, the above-described arrangement matrix is used. However, different from the first embodiment, the front / back determination is performed by the reverse rotation front / back determination unit 415. Here, the light source calculation is not performed. For example, in a virtual space that is a virtual three-dimensional space, zooming, scaling, rotation,
In addition to performing the translation / perspective transformation, when the contour drawing model acquisition unit 400 acquires a contour drawing model having the same size as the three-dimensional model, the contour drawing model processing unit 410 generates the contour line drawing model. Perform vertex transformation to expand. In this case, the relationship between the three-dimensional model and the contour drawing model is also as shown in FIG.

In the case of the contour drawing model according to the second embodiment, the front side is determined to be back, and the back side is determined to be front. Therefore, in the example of FIG. 16, the surface 61 on which the arrow points in the same direction as the direction of the line of sight 640 from the camera 650.
Only 3, 614, 615 and 616 are to be drawn.
Since this surface is usually a back surface, it is excluded from the drawing target, but is treated as a drawing target in the second embodiment. In this way, the surfaces 611 and 612 outside the three-dimensional model 600 and close to the camera 650 are excluded from the drawing target, so that the three-dimensional model 600 is drawn as usual.
Note that since the hidden surface is erased by the hidden surface erasure processing unit 435 of the pixel processing unit 430, not all of those surfaces are rendered even if they are to be rendered.

Blurred expression texture mapping section 420
Performs a process for mapping a blurred expression texture to a contour drawing model so that the resulting contour line becomes a blurred line. Since the outline does not necessarily need to be blurred, the blurred expression texture mapping unit 420 is selectively operated.

The three-dimensional model processing unit 440 performs processing of a three-dimensional model. That is, the three-dimensional model processing unit 4
40 is a vertex transformation (enlargement /
Reduction / rotation / translation / perspective transformation) and light source calculation are performed, and the front and back of each surface (or polygon) of the three-dimensional model is determined. In addition to performing enlargement / reduction / rotation / translation / perspective transformation in accordance with the state specified in the virtual three-dimensional space, the contour drawing model processed by the contour drawing model processing unit 410 is the same as the stereo model. If the size is the size, the three-dimensional model processing unit 440 performs vertex conversion for reducing the size of the three-dimensional model so that the three-dimensional model is relatively smaller than the contour drawing model. In this case, the relationship between the three-dimensional model and the contour drawing model also becomes as shown in FIG.

The determination of the front / back of the surface is the same as that of the normal model, that is, the opposite of the case of the contour drawing model.
Of the surfaces of 00, those whose arrows point in the same direction as the direction of the line of sight 640 of the camera 650 are excluded from the drawing target. In the example of FIG. 16, the rear surface 60 viewed from the camera 650.
3, 604, 605 and 606 are excluded from the drawing target. Here, the texture of the three-dimensional model
Processing for mapping is also performed.

The pixel processing section 430 performs a drawing process for each pixel. For example, the pixel processing unit 430 obtains the color of each pixel in the plane by interpolating from the color of the vertex of the plane,
The color of each pixel is determined while performing the hidden surface removal processing using the buffer. The pixel processing unit 430 performs the process on the surface to be drawn by the contour drawing model processing unit 410 and the stereo model processing unit 440.

For example, in the case of FIG.
The two faces 601 and 602 closest to the camera 650
Is drawn, and the distance 4 to the camera 650 of the contour drawing model is
Two surfaces 613, 614, 615 and 616 are drawn. Since these four surfaces of the contour drawing model 610 protrude left and right from the three-dimensional model 600 when viewed from the camera 650, only the protruding portions are drawn without erasing the hidden surface. This protruding part becomes the contour line. Note that the pixel processing unit 430 determines the color in consideration of the color of the material of the contour drawing model. In some cases, the color of the outline (color for black or dark outline) is used as the color of the outline drawing model ignoring the material color.

Next, a processing flow for the second embodiment will be described. The following process is a process performed by the arithmetic processing unit 103 in cooperation with other elements in the computer main body 101.

[CD-R Recording Process] FIG. 17 shows a process of generating a contour drawing model performed in advance in the second embodiment. When the process starts, data of the three-dimensional model stored in the HDD 107 in advance is read (step S353), and is acquired as a conversion target model.

Next, the size of the model to be converted is enlarged so as to be slightly larger (step S35).
5). For example, in the normal direction of each vertex of the conversion target model,
The vertex is moved by a length of 2% of the total length of the conversion target model, and is enlarged by about 2% as a whole. That is, for example, if the conversion target model is a humanoid and the height is equivalent to 1.8 m, each vertex is 0.0
It is moved by a length equivalent to 36 m. When the enlargement ratio is larger, the outline is drawn thicker, and when the enlargement ratio is smaller, and when the conversion target model is only slightly enlarged, the outline is drawn thinner. Furthermore, if the part is not uniform and is partially enlarged, only the outline of the enlarged part is drawn thick. Since this adjustment is usually performed by the maker of the three-dimensional model, a contour line reflecting the intention of the maker can be drawn.

When the normal of each vertex of the three-dimensional model is not defined, the normal of the vertex obtained by interpolating the normal of each face sharing the vertex is used to determine the normal of the vertex. Can be moved in the normal direction of the vertex.

Further, the plane can be moved in the normal direction of each plane of the three-dimensional model. However, if the surface is simply moved, a gap is generated between the surfaces, and a process for filling the gap is required separately. Furthermore, since the reference position is usually defined in the three-dimensional model, the reference position of the corresponding conversion target model is
Each vertex of the conversion target model can be moved.

Next, the color of the material on each surface of the model to be converted is set to a color having the same saturation but lower brightness (step S357). Note that all the surfaces may be set to a single color such as black. Further, the setting for mapping the texture for faint expression may be performed. Since the color of the material is adjusted by the maker,
The outline can be drawn in the color intended by the maker.

In the second embodiment, since the process of inverting each surface of the conversion target model is not performed, the data of the conversion target model processed so far is used as the outline drawing model /
The data is stored in the HDD 107 (step S36).
1), the contour drawing model generation process ends (step S363).

Next, various data including the contour drawing model data stored in the HDD 107 is written to the CD-R 131 by the CD-R drive 113. FIG.
, The example of data written to the CD-R 131 is the same as in the first embodiment. That is, in the program area 132, the computer 1000
A program for implementing the present invention.
This program may not include processing until writing to the CD-R 131. System data area 133
Stores various data processed by the program stored in the program area 132 described above.

Data including outline drawing model data 135 is stored in the image data area 134. Here, the front and back of each surface of the model indicated by the contour drawing model data are the same as the corresponding surfaces of the three-dimensional model. In addition, when the contour drawing model is generated in the contour drawing model acquisition process described later, the contour drawing model data 135 does not need to be stored. The sound data area 136 stores data for causing the sound processing unit 109 shown in FIG. 1 to output a sound from the sound output device 125.

Note that the size of the contour drawing model stored in the CD-R 131 may be defined to be the same as the size of the corresponding stereo model. In this case,
After the contour drawing model is acquired in the contour drawing model acquisition processing described later, the contour drawing model is enlarged until the arrangement matrix of the contour drawing model is set in the contour drawing model placement processing described later. Is done. Alternatively, when the arrangement matrix of the outline drawing model is set in the outline drawing model arrangement processing, the arrangement matrix may be determined so that the arrangement matrix includes the enlargement conversion. Conversely, when arranging the three-dimensional model, the three-dimensional model arrangement matrix may be determined so that the three-dimensional model arrangement matrix includes the reduction conversion.

The material color of each surface of the contour drawing model stored in the CD-R 131 may be the same as the material color of each surface of the corresponding three-dimensional model. In this case, the contour drawing model is drawn in a separately defined color such as black when drawing the contour drawing model described later.

[Overall Processing Flow] The processing flow of the level shown in FIG. 7 is the same as that of the first embodiment. That is, an initial setting is performed first (step S2).
This initial setting includes a data acquisition process (FIG. 18) of the contour drawing model described in detail later. Then, the state in the virtual space is set (step S3). At this time, a process of determining the position coordinates and the like of the contour drawing model is performed. Next, a process of determining whether or not to draw an outline is performed (step S4). If the contour is to be drawn, a drawing process of the contour drawing model is performed (step S5). This will be described later with reference to FIG. Then, the drawing of the three-dimensional model is performed regardless of whether the contour is drawn or not (step S6). Steps S3 to S6 are repeated until the processing is completed (step S7).

[Contour Drawing Model Acquisition Processing] FIG. 18 shows a contour drawing model acquisition processing. Here, first, it is determined whether or not a contour drawing model is generated (step S223). This is because there are a case where the contour drawing model is prepared in advance and a case where the contour drawing model is generated at this stage. Here, this determination is made, for example, when the contour drawing model corresponding to the three-dimensional model is CD-R1.
This is performed by determining whether or not the data is stored in the storage 31. If it is determined that the model is stored, it is determined that the contour drawing model is not generated. If it is determined that the model is not stored, it is determined that the contour drawing model is generated.

When it is determined that the contour drawing model is not generated, the data of the contour drawing model stored in the CD-R 131 is read (step S27).
7). As described above with reference to FIGS. 16 and 17, each surface of the contour drawing model has the same front and back surfaces as the corresponding surface of the three-dimensional model, unlike the first embodiment. The size of the contour drawing model to be read is defined to be slightly larger than the corresponding three-dimensional model. Further, the color of the contour drawing model is defined as a color darker than the corresponding three-dimensional model.

If it is determined that a contour drawing model is to be generated, a process for generating a contour drawing model is performed (step S225). As in step S227, even when the contour drawing model is generated at this stage, the surfaces of the contour drawing model are the same as the corresponding surfaces of the three-dimensional model (see FIG. 16).

The size of the contour drawing model is generated to be slightly larger than the corresponding three-dimensional model. Step S35
Similarly to FIG. 5 (FIG. 17), for example, the vertex is moved in the normal direction of each vertex of the three-dimensional model, and an enlarged contour drawing model is generated. If the outline drawing model is larger than the stereo model, the outline is drawn thicker,
If the contour drawing model is only slightly larger than the three-dimensional model, the contour is drawn finer.

As described in the description of step S355 (FIG. 17), even if the plane is moved in the normal direction of each plane of the three-dimensional model, an enlarged contour drawing model is generated. Good. Furthermore, an outline drawing model that is enlarged by moving each vertex of the stereo model around a reference position defined in the normal stereo model may be generated.

At this point, the size of the contour drawing model may be generated in the same size as the size of the corresponding three-dimensional model. In this case, after the contour drawing model is obtained in the contour drawing model acquisition processing, the contour drawing is performed until the contour drawing model arrangement matrix is set in the contour drawing model arrangement processing described later. Model is expanded. Alternatively, when the arrangement matrix of the contour drawing model is set in the contour drawing model arrangement processing, the arrangement matrix may be determined to include the enlargement conversion. Conversely, when arranging the three-dimensional model, the three-dimensional model arrangement matrix may be determined so that the three-dimensional model arrangement matrix includes the reduction conversion.

On the other hand, the material color of each surface of the contour drawing model is generated as a darker color of the material of each surface of the corresponding three-dimensional model. Step S35
7 (FIG. 17), the color of the contour drawing model to be generated may not be defined at this point. Alternatively, the color of the material of each surface of the contour drawing model may be the same as the color of the material of each surface of the corresponding three-dimensional model. In this case, when the contour drawing model is drawn, the color of the contour drawing model is not considered, and the contour drawing model is drawn with a separately defined color such as, for example, black, or a color of a texture expressing blur. Is done.

Next, it is determined whether or not a texture expressing blur is mapped on the contour drawing model (step S299). When the contour drawing model is generated in step S225, this determination is performed based on the data of the corresponding three-dimensional model. On the other hand, when the contour drawing model is read in step S227,
This determination is made based on the data of the read contour drawing model. If it is determined that a texture expressing blur is mapped, step S231 is performed.
Is mapped on the contour drawing model. That is, texture coordinates (U, V) are set for each vertex of the polygon.

As described above, the texture expressing the blur is a texture having a pattern including a change in lightness or transparency, such as the texture shown in FIG. When it is determined that the texture expressing the blur is not mapped, and when the process of mapping the texture ends, the arithmetic processing unit 103 ends the contour drawing model acquisition process (step S233).

[Contour Drawing Model Arrangement Processing] In step S3 of FIG. 7, the arrangement matrix of the contour drawing model is set, and the contour drawing model arrangement processing is performed.
Usually, the reference position of the contour drawing model is provided at a position corresponding to the reference position of the three-dimensional model. Then, such that the reference position of the contour drawing model is arranged at or near the position where the reference position of the three-dimensional model is arranged,
An arrangement matrix of the contour drawing model is set.

Here, when the direction of the three-dimensional model changes, an arrangement matrix including rotation conversion is set for the contour drawing model so as to correspond to the change. When the shape of the three-dimensional model changes, a deformation process is performed on the contour drawing model so as to correspond to the change.

At this stage, if the contour drawing model has the same size as the corresponding three-dimensional model, the contour drawing model is enlarged. More specifically, an arrangement matrix of the contour drawing model is set such that each vertex of the contour drawing model is enlarged and converted according to a predetermined enlargement ratio around the reference position of the contour drawing model. Or conversely, the three-dimensional model may be reduced. That is, in this case, the matrix for arranging the three-dimensional model is set such that each vertex of the three-dimensional model is reduced and converted in accordance with the predetermined reduction ratio with the reference position of the three-dimensional model as the center.

By doing so, finally, the relatively large contour drawing model is arranged so as to include the three-dimensional model. The contour drawing model may not completely include the three-dimensional model depending on the relationship between the arrangement positions, directions, shapes, and the like of the two models. However, even in such a case, the outline is drawn for the included part.

At this stage, it is not always necessary to set an arrangement matrix.
It is only necessary that the elements required for vertex conversion such as the direction and the enlargement / reduction ratio have been determined. Also in this case, the actual vertex conversion is performed at the stage of the rendering process of each model.

[Drawing Process of Contour Drawing Model] In FIG. 19 showing the drawing process flow of the contour drawing model, the process described below is repeated until all vertices of the contour drawing model are processed (step S523). ). The first process that is repeatedly performed is vertex transformation (enlargement / reduction / rotation / translation / perspective transformation) for one vertex (step S525). For example, this processing is performed by the geometric operation unit 207 instructed by the operation processing unit 103.

It should be noted here that the light source calculation is not performed on the contour drawing model. This is because the contour is irrelevant to the position of the light source and the like, and it is useless to calculate the light source (in some cases, the color of the material of the contour drawing model may be eventually ignored). Normally, this vertex transformation is performed based on the state specified in the virtual three-dimensional space. However, if the size of the contour drawing model is the same as the three-dimensional model, the vertex transformation is performed according to the arrangement matrix set in the arrangement processing. At this stage, the contour drawing model may be enlarged and converted.

Then, a process of determining whether or not the polygon (surface) including the vertex is a back surface based on a normal determination standard is performed (step S527). Normally, only the front surface is to be drawn, but in the case of the contour drawing model according to the second embodiment, the back surface is to be drawn according to the normal determination criteria. The determination in this step is performed in the case of a triangular polygon in which direction the triangular polygon composed of the two vertices processed before this vertex faces.

As shown in FIG. 11, for example, when each vertex of a triangular polygon is assigned a vertex number in a counterclockwise direction according to a normal judgment criterion, it is defined that the front side of the page is the front side (so-called front side). Right-handed). In the second embodiment, the criterion for the front / back determination is reversed, and when a vertex number is assigned clockwise, it is determined that the front side of the paper is the front side. Only the surface determined to be the front surface based on the reversed front / back determination criteria is set as a drawing target. As a result, the front side in the criterion of the second embodiment is determined to be the back side by the normal criterion.

FIG. 20 shows an example of a triangular polygon to be determined. Each vertex of the triangular polygon shown in FIG. 20 is assigned vertex numbers 0, 1, and 2 in the order of upper, lower left, and lower right in the figure. In the example of FIG. 20, the front side is the front side in terms of the numbering of the vertices, but according to the reversed criterion, the front side is the back side. In the case of the back surface according to the reversed judgment criterion, the front surface is normally removed from the drawing target because it is the front surface. Embodiment 2
Although the front / back determination is performed at this stage, the front / back determination may be performed before this stage.

If the polygon (surface) including the vertex is a front surface according to a normal criterion, step S5
Return to 23. If the polygon (surface) including the vertex is a back surface according to the normal determination criterion, a process of determining whether or not to map a texture expressing blur is performed (step S529). This means texture mapping for polygons. If the texture representing the blur is to be mapped, a process of calculating the texture coordinates of the texture for expressing the blur for the vertex is performed (step S531).
Here, as texture perspective processing,
Using Q = 1 / w (w is the depth from the screen),
The calculation of S = U × Q and T = V × Q is performed. If the texture expressing the blur is not mapped, the process proceeds to step S533.

Then, for example, the triangle drawing processing unit 205 and the pixel color processing unit 209 shown in FIG. 2 are driven (step S533). As described above, the triangle rendering processing unit 205 interpolates the data of each vertex of the triangle polygon to generate data at each pixel inside the triangle polygon. The data of each vertex is a material color, a screen coordinate value, and a texture coordinate value if step S531 is performed. The data at each pixel is the color of the material and the texel color if step S531 is performed. However, at this point, it is also possible to ignore the color of the material and set the color of the outline at each vertex. It is also possible to set the luminance in consideration of the color of the material. Pixel color processing unit 20
9 writes a display image in the frame buffer 213 using data of each pixel inside the triangular polygon generated by the triangular drawing processing unit 205. At this time, the hidden surface is erased using the Z buffer 211.

[Three-dimensional model drawing process] The three-dimensional model drawing process is not different from that of the first embodiment (FIG. 14). That is, the following processing is repeatedly performed until all vertices of the three-dimensional model are processed (step S603). The first processing that is repeated is vertex transformation (enlargement / reduction / rotation / translation / perspective transformation) and light source calculation for one vertex (step S605). This is, for example, the arithmetic processing unit 1
The arithmetic operation unit 207 executes the instruction from the instruction 03. The data of the three-dimensional model is stored in the CD-R 131, for example. When the contour drawing model has the same size as the three-dimensional model, the contour drawing model may be made relatively large by reducing the three-dimensional model. In this case, reduction conversion is performed in step S605.

Next, a process of determining whether or not the polygon (surface) including the vertex is a front surface is performed (step S60).
7). This determination is made in the case of a triangular polygon based on which direction the triangular polygon composed of two vertices processed before this vertex faces. If the polygon (plane) including the vertex is a back surface, the process returns to step S603. Polygon (face) containing the vertex
If is a front surface, calculation processing of the texture coordinates of the vertex is performed (step S609). Then, for example, the triangle drawing processing unit 205 and the pixel color processing unit 209 illustrated in FIG. 2 are driven (step S6).
11).

As described above, the triangle drawing processing unit 205
Generates data at each pixel inside the triangle polygon by interpolating the data of each vertex of the triangle polygon. The data of each vertex is a material color, a screen coordinate value, and a texture coordinate value. The data at each pixel is the material color and texel color. The pixel color processing unit 209 writes a display image to the frame buffer 213 using the data of each pixel inside the triangle polygon generated by the triangle drawing processing unit 205. At this time, the hidden surface is erased using the Z buffer 211.

When the above processing is performed, the three-dimensional model is rendered as usual, and the contour drawing model introduced in the second embodiment is a part of the surface behind the three-dimensional model that is not hidden by the three-dimensional model. Is drawn,
That part is rendered as an outline. In the second embodiment, the outline can be easily drawn by performing substantially the same processing as that of the normal three-dimensional model only by introducing the outline drawing model and reversing the front / back determination of the outline drawing model.

3. 4. Other Embodiments (1) In FIGS. 4 and 16, the surface of the contour drawing model and the surface of the three-dimensional model are one-to-one, but the number of surfaces of the contour drawing model can be reduced. . This is because if the number of surfaces is reduced, the processing speed is increased. However, the surface of the contour drawing model has a corresponding surface in the three-dimensional model.

(2) Steps S4 and S6 of the processing flow shown in FIG. 7 can be interchanged.

(3) Change of Hardware Used In the above-described embodiment, an embodiment is described in which the graphics processing unit 111 executes a part of the stereo model and contour drawing model drawing processing. However, the entire object drawing process may be performed by the graphics processing unit 111 or the arithmetic processing unit 103.

FIG. 1 is an example, and various changes can be made. For example, in the case of a game device, it is conceivable to provide the interface unit 117 with a memory card read / write interface for storing data. Whether or not to include the communication interface 115 is optional. Since the present invention is not directly related to sound processing, it is not necessary to provide the sound processing unit 109.

The CD-R is an example of a recording medium, and includes an internal memory such as a RAM, a floppy disk,
Other recording media such as a magnetic disk and a DVD-RAM may be used. In that case, the CD-R drive 113 needs to be a drive that can read and write on a corresponding medium. Further, according to the present invention, the processing up to writing on the recording medium and FIG.
Are independent of each other, and can be operated by different computers. FIG.
Since the computer shown in FIG. 7 only needs to be able to read from a recording medium, the computer that performs the processing shown in FIG. 7 may include a drive that can only read programs and data stored in the medium. I just need. That is, as a recording medium, an internal memory such as a ROM, a CD
-A mainly read-only recording medium such as a ROM, a DVD-ROM, and a memory cartridge may be used. In that case CD
-The R drive 113 needs to be a drive that can read the corresponding medium.

Further, the above is the case where the present invention is implemented by a computer program.
It is also possible to implement by combining a program and a dedicated device such as an electronic circuit, or by only a dedicated device such as an electronic circuit. At this time, FIGS. 7, 8, 10 and 1
4 or FIG. 7, FIG. 18, FIG. 19, and FIG. 14, the apparatus may be configured for each function represented by each step, or the apparatus may be configured for each part or combination thereof. Can be

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and can be appropriately changed without departing from the gist of the present invention. For example, in the above-described embodiment, a case has been described in which the present invention is implemented using a normal computer as a platform. However, the present invention may be implemented using a home-use game machine, an arcade game machine, or the like as a platform.
In some cases, personal digital assistants, car navigation systems,
It is also conceivable to use a system or the like as a platform.

Further, the programs and data for realizing the present invention are not limited to the form provided by a recording medium such as a CD-R detachable from a computer or a game machine. That is, programs and data for implementing the present invention are recorded in the memory of another device on the network 151 connected via the communication line 141 by the communication interface 115 shown in FIG. , This program or data is transmitted to the communication line 141.
May be sequentially stored in the memory 105 as needed and used.

[Display Example] FIG. 21 shows an image display example when the contour drawing model is automatically generated from the three-dimensional model and rendered in FIG. 8 or FIG. Contour lines are drawn around the tree trunk with approximately equal width. On the other hand, FIG.
FIG. 5 or FIG. 17 shows an example of a result of generating a contour drawing model in advance in FIG. 5 or FIG. 17 and reading out and rendering the previously generated contour drawing model. If a contour drawing model is appropriately created, a portion having a thin contour line or a thick portion can be arbitrarily created. For example, in FIG. 22, the contour is thinner at the top of the tree trunk, and the contour is thinner at the root of the tree trunk. In addition, FIG. 23 shows an example of a faint expression of a contour line. For example, when the texture as shown in FIG. 9 is mapped to the contour drawing model, the contour becomes partially missing as shown in FIG. As a result, it becomes possible to express a contour line that is drawn by hand.

As described above, when the present invention is used, a contour line can be represented on a three-dimensional model by a simple process. When a contour line is used, for example, a cel animation may be created. To create a cell animation by hand,
Due to the increased amount of manual work, images from too many scenes and angles cannot be created. Also, in a game in which a hand-written game character is displayed, it is not possible to create a character image from too many angles for the same reason. Since the present invention can be expressed by using computer graphics as in the present invention, an image of an arbitrary scene can be easily created.

[0163]

As described above, according to the present invention, a three-dimensional model arranged in a virtual space is drawn, and the inside of a contour drawing model corresponding to the three-dimensional model and including the three-dimensional model is drawn. As a result, a computer-readable recording medium storing a rendering method and apparatus and a rendering program for rendering contour lines of the three-dimensional model can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a computer that executes a program according to the present invention.

FIG. 2 is a block diagram illustrating an example of a graphics processing unit in FIG. 1;

FIG. 3 is a functional block diagram according to the first embodiment.

FIG. 4 is a schematic diagram for explaining a positional relationship among a camera, a three-dimensional model, and a contour drawing model according to the first embodiment. The direction in which the front surface of the three-dimensional model and the contour drawing model faces is indicated by an arrow.

FIG. 5 is a flowchart of a contour drawing model generation process according to the first embodiment;

FIG. 6 is a schematic diagram showing an example of data written on a CD-R 131.

FIG. 7 is a flowchart showing the entire processing of the present invention.

FIG. 8 is a flowchart of a contour drawing model acquisition process according to the first embodiment;

FIG. 9 is an example of a texture for faint expression.

FIG. 10 is a flowchart of contour drawing model drawing processing according to the first embodiment;

FIG. 11 is a schematic diagram for explaining front / back determination of a triangular polygon.

FIG. 12 is a schematic diagram for explaining a method of determining front and back.

FIG. 13 is a schematic diagram for explaining front / back determination of a triangular polygon in the first embodiment.

FIG. 14 is a flowchart of a stereo model drawing process according to the present invention.

FIG. 15 is a functional block diagram according to the second embodiment.

FIG. 16 shows a camera, a three-dimensional model,
FIG. 4 is a schematic diagram for explaining a positional relationship between a contour drawing model and a contour drawing model. The direction in which the front surface of the three-dimensional model and the contour drawing model faces is indicated by an arrow.

FIG. 17 is a flowchart of a contour drawing model generation process according to the second embodiment.

FIG. 18 is a flowchart of a contour drawing model acquisition process according to the second embodiment.

FIG. 19 is a flowchart of a contour drawing model drawing process according to the second embodiment.

FIG. 20 is a schematic diagram for explaining front / back determination of a triangular polygon in the second embodiment.

FIG. 21 is a display example of an image rendered using the present invention. This is the case of an automatically generated contour drawing model.

FIG. 22 is a display example of an image rendered using the present invention. Note that this is a case where a contour drawing model created by a human in advance is used.

FIG. 23 is a display example of an image rendered using the present invention. Note that this is a case where the texture for faint expression in FIG. 7 is mapped to the contour drawing model.

[Explanation of symbols]

1000 computer 101 computer main body 103 arithmetic processing unit 105 memory 107 HDD 109 sound processing unit 111 graphics processing unit 113 CD-R drive 115 communication interface 117 interface unit 119 internal bus 121 display device 125 sound output device 131 CD-R 141 communication medium 151 network 161 input device 201 bus control unit 205 triangle drawing processing unit
207 Geometric calculation unit 209 Pixel color processing unit 211 Z buffer 213 Frame buffer 300 Contour drawing model acquisition unit 305 Contour drawing model arrangement matrix setting unit 310 Contour drawing model processing unit 320 Blurring expression texture mapping unit 330 Pixel processing unit 335 Hidden surface removal processing unit 340 3D model processing unit 400 Contour drawing model acquisition unit 405 Contour drawing model arrangement matrix setting unit 410 Contour drawing model processing unit 415 Inversion front / back determination unit 420 Faint expression texture mapping unit 430
Pixel processing unit 435 Hidden surface removal processing unit 440 Solid model processing unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G06T 15/00 100 A63F 13/00

Claims (16)

(57) [Claims] 1. A rendering method for rendering a three-dimensional model composed of a plurality of surfaces arranged outside a represented object in a virtual space and representing the outside of the object, the method comprising: A first step of acquiring a contour drawing model in which a texture having a pattern including a change is mapped and a surface corresponding to each surface of the three-dimensional model is reversed, and storing the model in a first storage unit; A second step of arranging the contour drawing model at a position including the following; and drawing the three-dimensional model from a given viewpoint position and storing it in a second storage unit; A third step of drawing only the surface facing the table with a predetermined color scheme and storing the result in the second storage unit. 2. A rendering method for rendering a three-dimensional model composed of a plurality of planes having the outside of an object placed and represented in a virtual space as a front surface, the rendering method corresponding to the three-dimensional model and the front and back of the plane being A first step of acquiring the same contour drawing model and storing it in a first storage unit; a second step of arranging the contour drawing model at a position including the three-dimensional model; Draw from the position and store it in the second storage unit, and draw only a surface of the contour drawing model facing the viewpoint position with a predetermined color scheme and store it in the second storage unit. And a third step of performing the following. 3. The second step is a step of enlarging the size of the contour drawing model obtained in the first step and arranging the contour drawing model at a position including the three-dimensional model. 3. The rendering method according to claim 2, wherein: 4. A method of enlarging the size of the contour drawing model by moving each vertex of a surface constituting the contour drawing model obtained in the first step in a direction normal to each vertex. 3. The rendering method according to claim 2, further comprising the step of: arranging the contour drawing model enlarged in the fourth step at a position including the three-dimensional model, wherein the second step is a step including the three-dimensional model. . 5. The method according to claim 2, wherein the second step is a step of reducing the size of the three-dimensional model and arranging the contour drawing model at a position including the three-dimensional model. Rendering method. 6. The third step is to draw the three-dimensional model from a given viewpoint position,
A step of mapping a texture having a pattern including a change in lightness or transparency only on a surface of the contour drawing model facing the viewpoint, and drawing the surface. The rendering method according to claim 2, wherein 7. A computer-readable recording medium storing a program for rendering a three-dimensional model composed of a plurality of surfaces that are arranged in a virtual space and that represent the outside of an object to be represented, the program comprising: Obtains a contour drawing model in which a texture corresponding to the three-dimensional model and having a pattern including a change in lightness or transparency is mapped and the front and back of the surface corresponding to each surface of the three-dimensional model is inverted. A first step of storing the contour model in a position including the three-dimensional model; and a second step of drawing the three-dimensional model from a given viewpoint position. While storing in the storage unit, only the surface of the contour drawing model facing the table with respect to the viewpoint position is drawn with a predetermined color 2. A computer-readable recording medium, characterized by being a program for executing the following steps: 8. A computer-readable recording medium storing a program for rendering a three-dimensional model composed of a plurality of surfaces which are arranged in a virtual space and represent the outside of an object to be represented, the program comprising: A first step of acquiring a contour drawing model corresponding to the three-dimensional model and having the same front and back sides of the surface and storing the acquired model in a first storage unit; A second step of arranging a model, and drawing the three-dimensional model from a given viewpoint position and storing it in a second storage unit, and a surface of the contour drawing model facing the viewpoint position. A third step of drawing only a predetermined color scheme and storing it in a second storage unit. Recording medium that can be taken. 9. The computer-readable recording according to claim 8, wherein the first step is a step of acquiring a contour drawing model corresponding to the three-dimensional model and having a size larger than that of the three-dimensional model. Medium. 10. The second step is a step of enlarging the size of the contour drawing model obtained in the first step and arranging the contour drawing model at a position including the three-dimensional model. The computer-readable recording medium according to claim 8, wherein: 11. The method according to claim 8, wherein the second step is a step of reducing the size of the three-dimensional model and arranging the contour drawing model at a position including the three-dimensional model. Computer readable recording medium. 12. The third step includes: rendering the three-dimensional model from a given viewpoint position;
A step of mapping a texture having a pattern including a change in lightness or transparency only on a surface of the contour drawing model facing the viewpoint, and drawing the surface. 9. The computer-readable recording medium according to claim 8, wherein: 13. A rendering apparatus which renders a three-dimensional model composed of a plurality of surfaces arranged outside a represented object and arranged in a virtual space, wherein the three-dimensional model corresponds to the three-dimensional model. Acquiring means for acquiring a contour drawing model on which a texture having a pattern including a change is mapped and in which the front and back of a surface corresponding to each surface of the three-dimensional model are reversed, and storing the obtained model in a first storage unit; Arranging means for arranging the contour drawing model at a position to be included; drawing the three-dimensional model from a given viewpoint position and storing it in the second storage unit; Rendering means for rendering only the surface facing the front with a predetermined color scheme and storing it in the second storage unit. 14. A rendering apparatus which renders a three-dimensional model composed of a plurality of planes which are arranged in a virtual space and have the outside of an object to be represented as a front side, wherein the front and back sides of the plane correspond to the three-dimensional model. Acquiring means for acquiring the same contour drawing model and storing it in the first storage unit; arranging means for arranging the contour drawing model at a position including the stereo model; and arranging the stereo model from a given viewpoint position. Draw and store in the second storage unit, and draw only the surface of the contour drawing model that faces the viewpoint position with a predetermined color scheme and store it in the second storage unit. Means, and a rendering device. 15. A game device which renders a three-dimensional model composed of a plurality of surfaces which are arranged in a virtual space and which represent the outside of an object to be represented, comprising: a computer; and a program to be executed by the computer. did,
A computer-readable recording medium, wherein the program corresponds to the three-dimensional model, and a texture having a design including a change in brightness or transparency is mapped on the computer and corresponds to each surface of the three-dimensional model. An acquisition function of acquiring a contour drawing model whose surface is reversed and storing the model in a first storage unit; an arrangement function of arranging the contour drawing model at a position including the stereo model; Draw from a given viewpoint position and store it in the second storage unit, and draw only a surface of the contour drawing model that faces the table with respect to the viewpoint position with a predetermined color scheme. A drawing device stored in a storage unit, and a game device. 16. A game device which renders a three-dimensional model composed of a plurality of surfaces which are arranged in a virtual space and which represent the outside of an object to be represented, comprising: a computer; and a program to be executed by the computer. did,
An acquisition function of acquiring a contour drawing model corresponding to the three-dimensional model and having the same front and back surfaces, and storing the model in the first storage unit; An arrangement function of arranging the contour drawing model at a position including the three-dimensional model, drawing the three-dimensional model from a given viewpoint position and storing the three-dimensional model in a second storage unit; And a drawing function of drawing only a surface facing backward with respect to the viewpoint position with a predetermined color scheme and storing the drawing in a second storage unit.